Jar



Dec. 14, 1943.

F. N. OSMUN JAR Filed Aug. 18, 1941 2 Sheets-Sheet -1 3mm F2250 N. 06Ml/A ..0 AT A M A WXXZ? Patented Dec. 14, 1943 JAR Fred N. Osmun, Houston, Tex.

Application August 18, 1941, Serial No. 407,282

9 Claims.

This invention relates to a jar and has par-- ticular relation to a tool of the character described designed to be connected to a pipe stuck in a well bore and operable to transmit jars or vibration to the stuck pipe for releasing the same so that it can be pulled from the well.

An object of the invention is to provide a tool of the character described through which hydrostatic pressure in the well may be utilized to effeet the jarring action of the tool.

Another object of the invention is to provide a tool of the character described embodying a resilient member efiective to maintain the parts in inactive position and also forming a cushion after the blow has been struck.

More specifically the invention relates to a jar embodying a grappling member adapted, to be engaged with the stuck pipe, an anvil, a hammer and means whereby hydro-static pressure in the well may be utilized to project the hammer against the anvil to create the jarring action of the tool.

With the above and other objects in view the invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated in the accom panying drawings, wherein:

Figures 1 and 2 show vertical sectional views of the upper and lower ends, respectively, of the tool with the parts in position for delivering the hammer blow to the anvil.

Figure 3 shows a cross-sectional View taken on the line 33 of Figure 1.

Figure 4 shows a cross-sectional view taken on the line 44 of Figure 2.

Figures 5 and 6 show vertical sectional views, respectively, of the upper and lower ends of the tool in inactive position ready to be engaged with the stuck pipe.

Figure 7 shows a cross-sectional view taken on the line 71 of Figure 6, and

Figure 8 shows a side view of the tool, partly in section, in a well casing and connected to the stuck pipe and in readiness to deliver a blow.

Referring now more particularly to the drawings wherein like numerals of reference designate the same parts in each of the figures the numeral I designates the mandrel to the lower end of which a grapple 2 may be secured. This grapple may be of any selected form. As shown it con sists of a tapering tap which may be screwed into, and thereby engaged with the upper end of the stuck pipe 3. The mandrel l is provided with an axial channel 4 which continues on down through the grapple. I k

Working over the mandrel there isa tubular housing 5 screwed into the upperend of which there is a tubular coupling 6 whose lower end forms an anvil 1 and to theupp'er end of which an operating string 8, which extends to the ground surface, is connected. N

Screwed into the lower end of the housing 5 there is a gland 9 whose upper end closely surrounds the mandrel and whose lower end is internally flared so as to conform in shape to and. to closely surround a correspondingly flared portion 4a of the mandrel when the housing isin its lower position relative to the mandrelas" shown in Figure 6. The lower end of the gland 9 is formed with keys 9a adapted to intermesh with corresponding external keys 45 on the mandrel when the gland 9 is in said lower position as shown in Figure 6. 1

Above the gland 9 the mandrelis'formed with the external vertical keys In which are adapted to intermesh with corresponding internal keys H within the housing, said keys l0 being somewhat shorter than the keys ll so as to allow a limited vertical movement of the housing relative to the mandrel.

Seated on the upper ends or the'keys H there is a strong coil spring I2 and on this'springthe're is a suitable seal ring 13 forming a'seal between the mandrel and housing. 7

Within the housing and around the mandrel there is a locking sleeve 14 whose lower endis seated on the seal ring'l3 and fits closely about the mandrel as shown in Figures 1" and 5. The upper end of the mandrel, within the locking sleeve I4, is reduced in outside diameter. Screwed onto the upper end of the mandrel and'fitte'd within the locking sleeve I4 there is a stop coll'ar l5 and slidably mounted on the reduced upper end of the mandrel beneath said stop-collar there is an anchor ring Hi thus formingta charm. ber ll between said stop collar andanchor Within this chamber and between the stop col-.- l'ar and anchor ring there is'a strong coil spring I8.

Pivotally connected to, and dependiiig from, the anchor ring I6 there are thelockfng dogs!!! whose lower ends have the downwardly converging tapering faces 20, 2-I When the'tooli is in inactive position as shown inFi'gures 5 and the locking dogs will project -fz ibvvn into the registering grooves 22', 23ginfth'e insideof the locking sleeve 14 and in the exterior of; the man-. drel l as shown 'more'accurately in Figures 1 and with the faces 20, 2! in engagement with the correspondingly tapered faces 24, as shown in Figure 5, and the parts will be held in this inactive position while going into the well by the pressure of the spring [2.

Screwed into the upper end of the mandrel I there is a wash pip 26 which extends up into the coupling 5 and which is surrounded by a stufiing box 21 forming a seal between the upper end of the wash pipe and said coupling 6.

Slidably mounted on the wash pipe 25 between the anvil 'l and the upper end of the locking sleeve l5 there is a cylindrical hammer 28, which is freely movable.

It is contemplated that the chamber I! will be filled with liquid, such as clean oil and that.

there is a slight clearance between the locking sleeve [4 and the stop collar I5 so as to permit this liquid, when subjected to pressure, to pass above the stop collar l5. Also beneath the looking sleeve [4 the housing 5 is provided with one or more inlet ports 29 providing for the free inlet of the liquid contained within th well casing 38 and in which the tool is submerged. The column of liquid within the casing may extend to the top of the well so that the tool will be submerged in liquid having a high hydrostatic pressure.

The tool may be assembled as shown in Figures 5 and 6, with the chamber ll, Figure 5, filled with oil and with the lower ends of the dogs imaging the faces 24, 25 which are now in transverse registration. The grappling tool 2 may be now engaged with the stuck pipe 3. In the illustration shown this grappling is formed with a tapering tap which may be crewed into the upper end of thestuck pipe by suitable rotation of the tool. The intermeshing keys 9a, 4b, and 10, II, will transmit rotation from the operating string 8 and housing 5 to the mandrel and thence to the grappling tool. The operating string 8, together with the housing 5 may now be pulled upwardly relative to the mandrel into the position shown in Figures 2 and 8 and this will cause the anvil 'l to move upwardly relative to the hammer 28 causing a reduction of pressure in the chamber 3| thereby formed between the anvil and the hammer; also the spring 12 will be placed under greater compression since the locking sleeve M will be temporarily maintained in its relation to the mandrel by the locking dogs 19. The compression of the spring [2, however, will now be exerted through the dogs l9 against the anchor ring 15 tending to force the anchor ring l5 upwardly and placing the liquid in the chamber I"! under compression and as said liquid leaks by the stop collar 15 and passes above it, the dogs l9 and the anchor ring IE will gradually move upwardly placing the spring l8 under compression. It will be noted from an inspection of Figures 1 and 5 that the upper ends of the grooves 23 are widened inwardly as at 23a, Fig ure 5, and when the lower ends of the dogs are opposite said inwardly widened portions 23a of said grooves the tapering faces 25 acting against the tapering. faces 20 of the dogs will force said dogs inwardly thus releasing them from the lock ing sleeve [4. The hydrostatic pressure acting against the lower end of the seal ring [3 will now force said locking sleeve l4 upwardly very suddenly and with great force and the hammer 28 will be driven upwardly and will strike the anvil I with an intense blow. A jar will be thereby transmitted to the housing 5.

It will be noted from an inspection of Figure 2 that at this time the upper end of the gland 9 abuts the lower ends of the keys H! of the mandrel I and consequently the jar imparted to the housing 5 will be transmitted to the mandrel and the grappling tool and consequently to the stuck pipe 3. A single jar may release the stuck pipe 3; but if not, the operating string may be lowered until the parts again assume the position shown in Figure 5, the liquid leaking back from above the stop collar l5 into the chamber I! beneath said stop collar and the operation above detailed may be repeated as often as it is required to release the stuck pipe;

It may be here noted that the tension of the operating string is not relied on to actuate the hammer 28 but the hammer is actuated against the anvil by the hydrostatic pressure of the liquid in the well. Therefore, the operating string will not be subjected to sudden changes in tension and will not be so liable to part or be distorted as is the case with jars now commonly used where the tension of the operation string is relied upon for imparting the driving force to the hammer.

- When the blow has been struck by the hammer the spring 12 will also act to cushion the rebound.

The drawings and description are illustrative merely while the broad principle of the invention will be defined by the appended claims.

What I claim is:

1. A jar comprising two relatively movable parts, means for connecting. one of said parts to an object stuck in a well, an anvil on the other part, a hammer in the jar, means exposed to the hydrostatic pressure of the liquid in the well for actuating the hammer, yieldable means for retarding the movement of said hammer actuating means, upon relative longitudinal movement of the said parts, to cause a reduction in pressure between the anvil and hammer, and means for releasing said retarding means to allow said hydrostatic pressure to act to drive the hammer against the anvil to effect a jarring action.

2. A jar comprising two relatively movable parts,.means for connecting one of said parts to an object stuck in a well, an anvil on the other part, freely movable impact means in the jar exposed to the hydrostatic pressure of the liquid in the well, means engaging and temporarily retarding the movement of the impact means, upon relativ longitudinal movement of said parts, to create a partial vacuum between the anvil and the impact means, said holding means including a timing device effective to cause release of said retarding means to allow said hydrostatic pressure to act to drive the impact means against the anvil to efiect a jarring action.

3. A jar comprising two relatively movable parts, means for connecting one of said parts to an object stuck in a well, an anvil on the other part, means for preventing relative rotation of said parts, means allowing only a limited relative longitudinal movement of the parts, impact means in the jar exposed to the hydrostatic pressure of theliquid in the well, means engageable with impact means for retarding the movement of the impact means upon relative longitudinal movement of said parts to cause a reduction in pressure in the jar, said retarding means including a dash pot effective to control the release of said retarding-means to allow movement of the impact means under the influence of said hydrostatic pressure whereby the impact means will be driven against the anvil to efiect a jarring action.

4. A jar comprising two relative movable parts, means for connecting one of said parts to an object stuck in a well, an anvil on the other part, freely movable impact means in the jar exposed to the hydrostatic pressiue of the liquid in the well, releasable means retarding the movement of the impact means engageable with, and upon relative longitudinal movement of said parts, to cause a reduction of pressure between the anvil and the impact means, said retarding means being arranged to be released by the tension to allow said hydrostatic pressure to act to drive the impact means against the anvil to effect a jarring action and hydraulic means for controlling the time of such release.

5. A jar comprising two relatively movable parts, means for Connecting one of said parts to an object stuck in a Well, an impact face on one of the parts, impact means exposed to the hydrostatic pressure of the liquid in the well, means engageable with the impact means for retarding the movement of the impact means upon relative longitudinal movement of said parts to create a partial vacuum in the tool, means for releasing said retarding means being releasable upon a predetermined movement of the retarding means to allow an accelerated movement of the impact means, under the influence of said pressure, whereby the impact means wil1 be driven against said impact face to effect a jarring action.

6. A jar comprising two relatively movable parts, means for connecting one of said parts to an object stuck in a well, an impact face on one of the parts, freely movable impact means exposed to the hydrostatic pressure of the liquid in the well, means for retarding the movement of the impact means upon relative longitudinal movement of said parts to create a partial vacuum in the tool, said retarding means including releasable means engageable with the impact means and arranged to be released upon a predetermined movement of the retarding means to allow an accelerated movement of the impact means under the influence of said pressure whereby the impact means will be driven against said impact face to effect a jarring action.

'7. A jar comprising two relatively movable parts, means, for connecting one of said parts to an object stuck in a well, an impact face on one of the parts, impact means exposed to bydrostatic pressure of the liquid in the well, a dash-pot for retarding the movement of the impact means upon relative longitudinal movement of said parts to create a partial vacuum in the tool, means engageable with impact means and arranged to be released upon a predetermined movement of the dash-pot to allow an accelerated movement of the impact means, under the influence of said pressure, whereby the impact means will be driven against said impact face to effect a jarring action.

8. A jar comprising two relatively movable parts, means for connecting one of said parts to an object stuck in a well, an impact face on one of the parts, impact means exposed to the hydrostatic pressure of the liquid in the well, a dash-pot for retarding the movement of the impact means upon relative longitudinal movement of said parts to create a partial vacuum in the tool, said dash-pot including a yieldable member arranged to be placed under compres sion thereby, means releasable upon a predetermined movement of the dash-pot to allow an accelerated movement of the impact means, under the influence of said pressure, whereby the impact means will be driven against said impact face to efiect a jarring action.

9. A. jar comprising two relatively movable parts, means for connecting one of said parts to an object stuck in a well, an impact face on one of said parts, a freely movable rain in the jar exposed to the hydrostatic pressure of the liquid in the well, hydraulic means for retarding the movement of the ram upon relative longitudinal movement of said parts to cause a reduction of pressure between the ram and impact face, said retarding means also including means engageable with the ram and releasable therefrom upon a predetermined movement of the retarding means to allow an accelerated move ment of the ram under the influence of said hydrostatic pressure whereby the ram will be driven against the impact face to create a jar.

FRED N. OSM'UN. 

